Pressure loading device for printing roll



May 15, 1956 E. KUSTERS 2,745,342

PRESSURE LOADING DEVICE FOR PRINTING ROLL Filed May 6, 1950 3 Sheets-Sheet l INVENTOR. Eduard Kflsfers BY WW6M A f/orneys y 1956 E. KUSTERS 2,745,342

PRESSURE LOADING DEVICE FOR PRINTING ROLL Filed May 1950 3 Sheets-Sheet 2 F/GJ I /0 i i 35 i l i i 36 has;

H H H U f f X f G E{ WWW INVENTOR.

Eddara' KU'sfers A florneys May 15, 1956 E. KUSTERS PRESSURE LOADING DEVICE FOR PRINTING ROLL 3 Sheets-Sheet 3 Filed May 6, 1950 IIA -VIIJIIIIIIIIIIIIIIII ;"IIII.

INVENTOR. Eduard Kds/ers Fez a M Af/omeys against the main cylinder of a printing machine.

United PRESSURE LOADING nnvrcn non Pnnsrnvo ROLL Eduard Kiisters, Krefeld, Germany, assignor to Texplant Corporation, New York, N. Y., a corporation of New York Application May 6, 1950, Serial No. 160,51'32 Claims priority, application Germany March 10, 195% 8 Claims. (Cl. 101--247) The present invention relates to a pressure loading device suitable particularly for application to the printing rolls of singleand multi-color cylinder print machines.

Hitherto, two types of mechanisms have been adopted for maintaining a given pressure of the printing (15011 ne type employs a system of levers, rods and weights and another makes use of coil or leaf springs.

One of'the primary disadvantages of the lever and weight type mechanism is that it becomes extremely complicated and cumbersome, especially when 6, 8 or more printing rolls are used in a given printing machine. The reason for this is that each end of each printing roll has its own system of levers and rods and preferably also its own weight, which acts through the various levers and rods to urge the printing roll against the main cylinder. Another important disadvantage of this type of mechanism is that the inertia of the levers and rods and especially of the weight, as well as the frictional and other forces that must be overcome to move a given weight by movement of the system of levers and rods, is so great as to, in efiect, counteract any tendency of the printing roll to follow any irregularities in the contour of the main cylinder or in the web to be printed. This makes it necessary to seek a compromise between the pressure that should be applied by the printing roll and the pressure that can be applied without having the printing roll bounce away from the web when, for example, it passes over a seam in the web.

One of the primary disadvantages of the spring-type loading that has been in use for a considerable number of years is that the react on force of the rather strong compression springs that are required increases at a very high rate upon compression. Here again, a compromise must be arrived at between a sprin capable of exerting the desired pressure for normal printing and a spring strong enough to resist bouncing While resilient enough to give way when the printing roll passes over an irregularity such as a seam in the web.

It is well known that next to proper registry of the printing rolls relative to one another on a given machine, it is most important that their pressure against the main cylinder be substantially uniform regardless of any, irregularities in the periphery of the main cylinder or in the Web to be printed. The present invention is addressed particularly to the problem posed by the latter requirement.

Generally, the present invention contemplates a pneumatic pressure loading device that is capable of urging the printing roll toward the main cylinder with a substantially constant force so as to enable the printing roll to follow any irregularities on the periphery of the main cylinder or in the web without bouncing or skipping. In a preferred embodiment of the invention the pneumatic system is made to exert its force upon the bearing of the printing roll through the medium of a hydraulic liquid. The preference for this embodiment e 2,745,342 Patented May 15, 1956 is due primarily to the fact that leakage of compressible fiuid in the pneumatic system is completely avoided by the use of a hydraulic liquid in those portions of the device wherein there are moving parts.

The device of this invention may readily be applied to existing printing machines. In these machines the shaft at each end of a printing roll is journaled in a bearing mounted for movement relative to the side frame of the printing machine in a direction radial to the main cylinder. The position of the bearing relative to the periphery of the main cylinder is usually set initially by axial movement of a threaded spindle. During operation of the machine the desired pressure, urging the bearing and therefore the printing roll against the periphery of the main cylinder, is applied to the bearing through the spindle by means of either a compression spring or a system of levers, rods and weights. In accordance with the present invention the spring or levers, rods and weights are replaced by a pneumatic system including essentially a cylinder and piston, or a diaphragm, and a source of compressible fluid such as air. The pressure of the fluid in the pneumatic system, acting either directly or indirectly on the piston in the cylinder, is transmitted either directly or indirectly to the bearing for the printing roll.

The pneumatic system of this invention has the outstanding advantage over those hitherto proposed of urging the printing roll toward the main cylinder with a substantially constant force regardless of any irregularities in the surface of the cylinder or in the web to be printed. If the printing roll should pass over a slight depression in the web or in the main cylinder, the compressible fluid in the pneumatic system will expand a corresponding amount while maintaining substantially the same pressure. On the other hand, if the printing roll should pass over a scam in the webto be printed, the compressible fluid will contract a corresponding amount in the pneumatic system without any appreciable increase in pressure.

Another embodiment of the invention comprises a unique system and device for controlling the pressure of the compressible fluid in each of the pneumatic systems for each of the printing rolls. ment contemplates the use of a flexible coupling in the supply line for the compressible fluid which, when pinched closed by a spring biased lever, has been found far more effective in reducing leakage losses than the conventional valve arrangements.

The advantages and utility of the present inventionv will become further apparent from the following description with reference to the accompanying drawings wherem:

Figure 1 is a schematic view in elevation of a portion of a multi-co-lor printing machine;

Figure 2 is a diagrammatic illustration of one embodi- Figure 3 is a view in cross section taken along section line 55 of Figure 4 looking in the direction of the arrows;

Figure 6 is a view control panel;

Figure 7 is an end view, partly in trol panel shown in Figure 6;

Figure 8 is a detailed view in cross section of one of the control mechanisms shown in Figure 6; and

section, of the con- Figure 9 is a view in cross section taken along section" One such arrange in elevation, partly in section, of a in turn is pivotally mounted at- 16 to aside frame 17 ofv the machine, only a portion of a side frame being shown. The bell crank 14, as shown in Figure l, is urged to move ina clockwise direction around pivot 16 and thereby to press the surface of the printing roll 11 against the material to be printed, which travels around the main cylinder 10, by a pressure loading device consisting in part of a threaded spindle 19 mounted for endwise movement in a bushing 20 aflixed pivotally to the side frame member 17 at point 21 and carrying a cylinder 22 provided with a piston 24 and apiston rod 26, the latter being pivotally connected to the bell crank 14 at 27.

Referring now to Figure 2, which shows the pressure loading device in greater detail, the cylinder 22 is connected, by means of a conduit 29, to a pressure vessel'30 which is preferably provided with a valve connection 31 and amanometer or pressure gauge 32.

In operation, the pressure within the pneumatic system, i. e., the cylinder 22 to the right of the piston 24, the conduit 29 and the pressure vessel 30, is adjusted to a preselected level by the entrance or exit of a compressible. fluid such as air through the valve connection 31. 'The.

setting of the printing roll 11 is adjusted by rotation of the spindle 19 until the desired pressure of the printing roll against the main cylinder is attained. While it is within the scope of the invention to use a compressible fluid only, it is preferable to transmit the pressure of this fluid to the piston 24 through the medium of a suitable hydraulic liquid in order to minimize the possibility of leakage and a consequent loss of pressure. For this reason, the pneumatic system contains sufiicient hydraulic liquid to at least fill the cylinder 22 behind the piston, i. e., to the right of piston 24 as seen in Figure 2, when 'the piston is in its extreme position adjacent the left end of the cylinder.

During operation of the printing machine, the pneumatic system is preferably closed. The pressure of the compressible fluid in the system, acting through the medium of the hydraulic liquid on the piston 24, urges the printing roll 11 to follow any irregularities in the contour of the main cylinder '10 or in the web being printed by applying to the roll, by way of piston rod 26,

bell crank 14 and bearing 12, a substantially uniform pressure.

Referring now to Figure 3, the main cylinder of a printing machine is shown at 10 and one of the printing rolls urged against the periphery of, the cylinder is shown at 11. The shaft 34 of the printing roll 11 carries a drive gear 35 and is journaled in a bearing 36 supported on a bearing support member 37 movable radially of the main cylinder 10 and slidable on a side frame member 39. The movable bearing support member 37 is further provided with a cylinder 47 connected as shown by a conduit 49 to a vessel 50 containing a supply of hydraulic liquid suflicient at least to keep the cylinder 47 filled therewith. A piston 51 is provided within the cylinder 47 and connected to a spindle 52 threaded in a bushing 54 attached to the side frame member 39 of the machine.

The top of the vessel 50 is connected, by line 56, to a pressure chamber 57 containing a compressible fluid such as air orthe like. The pressure chamber 57 is connected to a source of compressible fluid 59 by way of branch line 60and a three-way valve 61 operable by actuation of a handle 62 on a control panel 64 provided with a pressure gauge 66.

In operation, the pressure the pneumatic system, i. e., the cylinder 47, conduit 49, vessel 50, line 56, pressure chamber 57 and branch line 60, is adjusted to apres'electe'd level by operation of three-way valve 61.

The position of the printing roll 11 relative to, and the pressure thereof against the main cylinder 10 is set by turning the spindle S2 to move the entire assembly, consisting essentiallyof the bearing support member 37 and the printing roll 11. Upon encountering any irregularities in the peripheral surface of the main cylinder 10 or in the Web that is printed, the printing roll 11 will .move laterally to follow those irregularities. Thus, for example, if the printing roll 11 should momentarily be urged away from the main cylinder 10, e. g., in going over a scam in the web, the pressure in the chamber 57 acting by way of line 56 on the hydraulic liquid in the vessel'50 and the resulting pressure of the hydraulic liquid on the piston 51 will yieldingly counteract such a force. If it should be desirable at anytime to reduce the pressure in pressure chamber 57, that can be accomplished by turning the three-Way valve 61 to discharge some of the compressible fluid into a discharge line 67.

Referring now to Figures 4 and 5, the printing roll 11 is journaled in a bearing member slidable radially of the main cylinder 10 and in a side frame member 71. The bearing member 70 is connected to a spindle 72 threaded in a bushing 74 mounted for limited axial movement in the side frame member 71. pivotally aflixed to the side frame member 71 by a pin connection 77 and the free end of the lever bears against a piston 79 mounted for movement in a first cylinder 80 communicating with a second cylinder 81 by a line or conduit $2. The second cylinder 81 is connected to a suitable source of compressible fluid by the line 84. Preferably, the cylinder 80 is filled, and the cylinder 81 is partly filled with a suitable hydraulic liquid 86, as shown. A portion of the lever 76 intermediate the free and pivoted ends thereof is in abutment with the bushing 74. r

ln operation, the pressure of the compressible fluid pressible fluid in cylinder 81 and line 84 which is there-v by momentarily subjected to further compression.

In the preferred arrangement illustrated in Figures 6 and 7, and in more detail in Figures 8 and 9, a supply line 87 for the compressible fluid passes behind a control panel 89 and is divided into as many branch-lines as there are pressure loading installations on the printing machine. Each'branch line 90 is connected to the main supply line 87 by way of two flexible couplings 91 and 92 and provided with a manometer or pressure gauge connection 94 intermediate the two flexible couplings. Each of the flexible couplings, as illustrated in greater detail in Figures 8 and 9, is provided on one side with a spring loaded lever 96 and on the other side with a pin 97. p

'In operation both levers 96 for the two flexible couplings on one branch line 90 are moved to the open position to supply the branch line with compressible fluid from supply line 87. The lever operating the flexible coupling 91 is then closed by releasing it so that the pressure gauge 66 will indicate the pressure in the individual branch line 90. The lever 96 for the other. flexible-coupling is then preferably also released to the closed position to squeeze off the coupling and seal completely the branch line 90. a

It is to be understood that many alterations and variations of the structures specifically disclosed will suggest themselves to those skilled in the art upon'reading this description. Thus, for example, it is possible to'substitute for the pneumaticsystem a hydraulic system provided with a stand pipe and a floating weight to maintain A lever 76 is Whenever the printing roll 11 encounters any i1'-.

a constant pressure on the hydraulic liquid. All such alterations and variations are intended to be included within the scope of this invention as defined within the appended claims.

I claim:

1. In a roll printing machine for printing a continuous textile web, a main cylinder, a printing roll having a movable bearing for each of its shaft ends, pneumatic pressure means acting upon each bearing for urging said printing roll against said main cylinder, and a mechanical adjustment for said pneumatic pressure means, said pneumatic pressure means including a cushioned body of fluid between the point of application of pressure to the movable bearing of said printing roll and said mechanical adjustment, whereby both the force of said pneumatic pressure means and that of said mechanical adjustment act upon the point where pressure is applied to said movable bearing.

2. Apparatus according to claim 1, wherein the pressure is applied to the cushioned body by compressed air, and said mechanical adjustment includes a piston in contact with the cushioned body.

3. Apparatus according to claim 2 wherein the cushioned body consists of a chamber filled with liquid, and the supply of liquid to said chamber is subjected to the force of compressed air.

4. Apparatus according to claim 3 wherein the liquid in the chamber and the supply of liquid thereto are sufficient to keep the chamber filled with liquid under extreme movement of the movable bearing.

5. Apparatus according to claim 3 wherein a vessel is embodied in the compressed air feed-in of the cushioned body.

6. Apparatus according to claim 5 wherein the vessel is partly filled with supply liquid supplied to the chamber and wherein pneumatic pressure acts upon the surface of the liquid in the vessel to apply pressure within the chamber.

7. Apparatus according to claim 6 wherein means is provided for cutting off the supply of pneumatic fluid from the vessel after a predetermined pressure has been applied thereto.

8. Apparatus according to claim 6 wherein the me chanical adjustment is fixed to the frame of the roll printing machine and is adjustable radially of the main cylin der, and provides an abutment for said pneumatic pressure means.

References Cited in the file of this patent UNITED STATES PATENTS 220,479 Johnson Oct. 14, 1879 844,350 Hale Feb. 19, 1907 2,112,453 Dauphinais Mar. 29, 1938 2,205,720 Goebel et al. June 25, 1940 FOREIGN PATENTS 618,016 Great Britain Feb. 15, 1949 

